73K321L Datasheet, PDF (8/24 Pages) TDK Electronics – CCITT V.23, V.21 Single-Chip Modem

73K321L
CCITT V.23, V.21
Single-Chip
CONTROL REGISTER 0
D7
D6
CR0 _TRANSMIT
0
000 _{MODE 4}
BIT NO.
D0
NAME
Answer/
Originate
D1
Transmit
Enable
D7, D5, D4, D2
Transmit
Mode
D6, D3
Unused
D5
TRANSMIT
MODE 3
D4
TRANSMIT
MODE 2
D3
D2
D1
D0
0 TX DTMF TRANSMIT ANSWER/
ENABLE
ORIGINATE
CONDITION
0
DESCRIPTION
Selects Answer mode in V.21 (transmit in high band,
receive in low band) or in V.23 mode, receive at1200 bit/s
and transmit at 75 bit/s.
1
0
1
D7 D5 D4 D2
0 0 00
0 0 01
0 1 10
1 1 10
N/A
Selects Originate mode in V.21 (transmit in low band,
receive in high band) or in V.23 mode, receive at 75 bit/s
and transmit at 1200 bit/s. If in V.23 and D2 of TR=1,
selects V.23 full duplex operation in 4-wire configuration.
Note: This bit works with TR bit D0 to program special
tones detected in Tone Register. See detect and tone
registers.
Disables transmit output at TXA.
Enables transmit output at TXA.
Note: Answer tone and DTMF TX control require TX
enable.
Power Down
Transmit DTMF
V.23 Mode
V.21 Mode
Not used; must be written as “0”
8